This thesis examines the transition between working-class radicalism and labour politics in two provincial English constituencies, Bristol and Northampton, between 1867 and 1918. By combining local case studies with a textual analysis of empirical material and a conceptual approach to ideology, it offers fresh insights into popular political change in late nineteenth- and early twentieth-century Britain. Its central argument is that, contrary to the prevailing historiography on labour politics and identity, a distinctive sense of class could shape working-class radical and labour strategies, languages, identities, and ideologies continuously between 1867 and 1918. In particular, it demonstrates that before the mid-1880s, working-class radical activists in Bristol and Northampton exhibited a non-adversarial sense of class that shaped their perceptions of the social order, their interpretations of radical ideology, and their relationships with both mainstream liberals and middle-class radicals. It also suggests that while working-class radicals came to use 'labour' to describe themselves and their organisations from the mid-1880s, this was primarily a rhetorical move rather than one reflecting a substantive change in their political identity. Over the next thirty years, labour activists in both Bristol and Northampton remained fiercely committed to the dominant strategy, the non-conflictual conception of class, and the political ideology that had long shaped local working-class radical traditions. In these constituencies, the Victorian tradition of working-class radicalism left an indelible mark on twentieth-century labour politics. This study has important implications for our understanding of political and ideological change in modern Britain. Firstly, confirming the existence of a decidedly working-class radical movement makes it easier to understand the rise of a class-based labour politics in late Victorian Britain without having to account for either discontinuities in popular politics or the re-emergence of a dormant class consciousness within the British working class. Secondly, establishing a line of continuity between working-class radicalism and later labour politics helps us to explain some of the tensions that characterised progressive politics in the Edwardian era. Finally, seeing working-class radicalism as a distinctive ideology with its own conceptual framework enriches our understanding of non-liberal progressive thought in the late nineteenth and early twentieth century.